I am working on an EMF- blocking fence for my property, which will probably be composed of pallets (stacked 2 high, with fenceposts in between). The walls of the pallets will be filled with different layers of bioabsorbant materials (sand-painted cardboard, fiberglass window screen, maybe Twizzlers :) ). Then over the front I'll screw sheets of plywood. I'll use different materials for different pallets and test each one with the meter (there is a broadband power line at the front border of my property, so that is the direction the signals will be coming from). I'll probably do display signs and make it into an interactive teaching exhibit.